Boron free automotive gear oil

ABSTRACT

The present invention provides a boron-free oil soluble lubricant additive package having a succinimide dispersant, an antiwear agent, and an extreme pressure agent, with a total phosphorus content of 500 ppm or less. The lubricating oils of this invention can pass both the ISOT and L60-1 tests, even in the absence of boron.

TECHNICAL FIELD OF THE INVENTION

The present invention is in the field of lubricant additives andlubricant formulations. Specifically, the present invention relates to aboron-free lubricant additive package that is capable of passing testsfor which the presence of boron was thought to be essential to passing.

BACKGROUND OF THE INVENTION

Historically, boron-containing lubricants have been used to attainsatisfactory performance against standard industry tests. Two suchindustry tests are the ISOT and the L60-1. However, boron impartscertain undesirable properties to the lubricant such as moisturesensitivity and increased price. Thus, it is desirable to have alubricant that can provide the performance demanded by industry whilereducing or eliminating the presence of boron. Recently, a boron-freelubricant additive package has been developed that unexpectedly passesboth the ISOT standard test and the L60-1 standard test.

SUMMARY OF THE INVENTION

The present invention provides a lubricating additive package that iscapable of passing both the ISOT standard test and the L60-1 standardtest. More specifically, the present invention in an embodiment providesan oil soluble lubricant additive package comprising: (a) a succinimidedispersant, (b) an antiwear agent, (c) an extreme pressure additive,wherein the weight ratio of said dispersant to said extreme pressureadditive is from about 1:7 to about 1:2, and wherein the package isboron-free, and wherein the total phosphorus content of the package isnot more than about 500 ppm.

In another embodiment is provided a lubricating oil comprising: (a) abase oil; and (b) the oil soluble lubricant additive package taughtherein.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

In accordance with the foregoing summary, the following presents adetailed description of one embodiment of the invention that iscurrently considered to be the best mode.

We begin with a discussion of the various components employed in certainembodiments of the present invention. Then we present a lubricantadditive package of the present invention and an example of a lubricantoil comprising the inventive lubricant additive package. We concludewith a discussion of the L60-1 and ISOT test performance attained by theinventive lubricant additive package.

Base Oil

The base oils useful herein include natural lubricating oils, syntheticlubricating oils, and mixtures thereof. Suitable lubricating oils alsoinclude basestocks obtained by isomerization of synthetic wax and slackwax, as well as basestocks produced by hydrocracking the aromatic andpolar components of the crude. In general, both the natural andsynthetic lubricating oils will each have a kinematic viscosity rangingfrom about 1 to about 40 mm²/s (cSt) at 100° C., although typicalapplications will require each of the base oils to have a viscosityranging from about 1 to about 16 mm²/s (cSt) at 100° C., preferably 2 to15 mm²/s (cSt) at 100° C. Natural lubricating oils include animal oils,vegetable oils (e.g., castor oil and lard oil), petroleum oils, mineraloils, and oils derived from coal or shale. The preferred naturallubricating oil comprises mineral oil.

The mineral oils useful in this invention can include but are notlimited to all common mineral oil base stocks. This would include oilsthat are naphthenic or paraffinic in chemical structure. Oils that arerefined by conventional methodology using acid, alkali, and clay orother agents such as aluminum chloride, or be extracted oils produced,for example, by solvent extraction with solvents such as phenol, sulfurdioxide, furfural, dichlorodiethyl ether, etc. They may be hydrotreatedor hydrorefined, dewaxed by chilling or catalytic dewaxing processes, orhydrocracked. The mineral oil may be produced from natural crude sourcesor be composed of isomerized wax materials or residues of other refiningprocesses. In one embodiment, the oil of lubricating viscosity is ahydrotreated, hydrocracked and/or iso-dewaxed mineral oil having aViscosity Index (VI) of greater than 80, preferably greater than 90;greater than 90 volume % saturates and less than 0.03 wt. % sulfur.

Group II and Group III basestocks are also particularly suitable for usein the present invention, and are typically prepared from conventionalfeedstocks using a severe hydrogenation step to reduce the aromatic,sulfur and nitrogen content, followed by dewaxing, hydrofinishing,extraction and/or distillation steps to produce the finished base oil.Also useful herein are base oils known as Group III, ≦0.03 wt. % sulfur,and ≧90 vol % saturates, viscosity index >120; and Group IV,poly-alpha-olefins. Hydrotreated basestocks and catalytically dewaxedbasestocks, because of their low sulfur and aromatics content, generallyfall into the Group II and Group III categories.

There is no limitation as to the chemical composition of the variousbasestocks used in the present invention. For example, the proportionsof aromatics, paraffinics, and naphthenics in the various Group I, GroupII and Group III oils can vary substantially. The degree of refining andthe source of the crude used to produce the oil generally determine thiscomposition. In one embodiment, the base oil comprises a mineral oilhaving a VI of at least 110.

The lubricating oils may be derived from refined, re-refined oils, ormixtures thereof. Unrefined oils are obtained directly from a naturalsource or synthetic source (e.g., coal, shale, or tar sands bitumen)without further purification or treatment. Examples of unrefined oilsinclude shale oil obtained directly from a retorting operation,petroleum oil obtained directly from distillation, or an ester oilobtained directly from an esterification process, each of which is thenused without further treatment. Refined oils are similar to theunrefined oils except that refined oils have been treated in one or morepurification steps to improve one or more properties. Suitablepurification techniques include distillation, hydrotreating, dewaxing,solvent extraction, acid or base extraction, filtration, andpercolation, all of which are known to those skilled in the art.Re-refined oils are obtained by treating used oils in processes similarto those used to obtain the refined oils. These re-refined oils are alsoknown as reclaimed or reprocessed oils and are often additionallyprocessed by techniques for removal of spent additives and oil breakdownproducts.

Synthetic lubricating oils include hydrocarbon oils and halo-substitutedhydrocarbon oils such as oligomerized, polymerized, and interpolymerizedolefins; alkylbenzenes; polyphenyls; and alkylated diphenyl ethers,alkylated diphenyl sulfides, as well as their derivatives, analogs, andhomologs thereof, and the like. Preferred synthetic oils are oligomersof α-olefins, particularly oligomers of 1-decene, having a viscosityranging from about 1 to about 12, preferably 2 to 8, mm²/s (cSt) at 100°C. These oligomers are known as poly-α-olefins or PAOs.

Synthetic lubricating oils also include alkylene oxide polymers,interpolymers, copolymers, and derivatives thereof where the terminalhydroxyl groups have been modified by esterification, etherification,etc. This class of synthetic oils is exemplified by polyoxyalkylenepolymers prepared by polymerization of ethylene oxide or propyleneoxide; the alkyl and aryl ethers of these polyoxyalkylene polymers(e.g., methyl-polyisopropylene glycol ether having an average molecularweight of 1000, diphenyl ether of polypropylene glycol having amolecular weight of 100-1500); and mono- and poly-carboxylic estersthereof (e.g., the acetic acid esters, mixed C₃-C₈ fatty acid esters,and C₁₂ oxo acid diester of tetraethylene glycol).

Another suitable class of synthetic lubricating oils comprises theesters of dicarboxylic acids (e.g., phthalic acid, succinic acid, alkylsuccinic acids and alkenyl succinic acids, maleic acid, azelaic acid,subric acid, sebasic acid, fumaric acid, adipic acid, linoleic aciddimer, malonic acid, alkylmalonic acids, alkenyl malonic acids, etc.)with a variety of alcohols (e.g., butyl alcohol, hexyl alcohol, dodecylalcohol, 2-ethylhexyl alcohol, ethylene glycol, diethylene glycolmonoethers, propylene glycol, etc.). Specific examples of these estersinclude dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexyl fumarate,dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctylisothalate, didecyl phthalate, dieicosyl sebacate, the 2-ethylhexyldiester of linoleic acid dimer, and the complex ester formed by reactingone mole of sebasic acid with two moles of tetraethylene glycol and twomoles of 2-ethyl-hexanoic acid, and the like. A preferred type of oilfrom this class of synthetic oils is adipates of C₄ to C₁₂ alcohols.

Esters useful as synthetic lubricating oils also include those made fromC₅ to C₁₂ monocarboxylic acids and polyols and polyol ethers such asneopentyl glycol, trimethylolpropane pentaeythritol, dipentaerythritol,tripentaerythritol, and the like.

Silicon-based oils (such as the polyalkyl-, polyaryl-, polyalkoxy-, orpolyaryloxy-siloxane oils and silicate oils) comprise another usefulclass of synthetic lubricating oils. These oils include tetra-ethylsilicate, tetra-isopropyl silicate, tetra-(2-ethylhexyl) silicate,tetra-(4-methyl-2-ethylhexyl) silicate, tetra-(p-tert-butylphenyl)silicate, hexa-(4-methyl-2-pentoxy)-disiloxane, poly(methyl)-siloxanesand poly (methylphenyl) siloxanes, and the like. Other syntheticlubricating oils include liquid esters of phosphorus containing acids(e.g., tricresyl phosphate, trioctylphosphate, and diethyl ester ofdecylphosphonic acid), polymeric tetra-hydrofurans, poly-alpha-olefins,and the like.

Dispersants

Dispersants derived from polyisobutylene (PIB) or mixedbutane-substituted succinimides are among the succinimide dispersantsuseful herein, where the molecular weight range of the PIB isapproximately 900-2100, most especially MW range 1200-1500. In oneembodiment, the succinimide is malienated to a succinic anhydride to PIBratio of approximately 1.0-1.25. The polyisobutylene succinic anhydrideintermediate can be further reacted with a suitable amine including anymono-, di-, or polyamine.

The dispersant may comprise one or more of various types of ashlessdispersants including succinimides, succinamides, succinic esters, andsuccinic ester-amides.

Methods for the production of the foregoing types of ashless dispersantsare known to those skilled in the art and are reported in the patentliterature. For example, the synthesis of various ashless dispersants ofthe foregoing types is described in such patents as U.S. Pat. Nos.2,459,112; 2,962,442, 2,984,550; 3,036,003; 3,163,603; 3,166,516;3,172,892; 3,184,474; 3,202,678; 3,215,707; 3,216,936; 3,219,666;3,236,770; 3,254,025; 3,271,310; 3,272,746; 3,275,554; 3,281,357;3,306,908; 3,311,558; 3,316,177; 3,331,776; 3,340,281; 3,341,542;3,346,493; 3,351,552; 3,355,270; 3,368,972; 3,381,022; 3,399,141;3,413,347; 3,415,750; 3,433,744; 3,438,757; 3,442,808; 3,444,170;3,448,047; 3,448,048; 3,448,049; 3,451,933; 3,454,497; 3,454,555;3,454,607; 3,459,661; 3,461,172; 3,467,668; 3,493,520; 3,501,405;3,522,179; 3,539,633; 3,541,012; 3,542,680; 3,543,678; 3,558,743;3,565,804; 3,567,637; 3,574,101; 3,576,743; 3,586,629; 3,591,598;3,600,372; 3,630,904; 3,632,510; 3,632,511; 3,634,515; 3,649,229;3,697,428; 3,697,574; 3,703,536; 3,704,308; 3,725,277; 3,725,441;3,725,480; 3,726,882; 3,736,357; 3,751,365; 3,756,953; 3,793,202;3,798,165; 3,798,247; 3,803,039; 3,804,763; 3,836,471; 3,862,981;3,936,480; 3,948,800; 3,950,341; 3,957,854; 3,957,855; 3,980,569;3,991,098; 4,071,548; 4,173,540; 4,234,435; 5,137,980 and Re 26,433,herein incorporated by reference.

In some embodiments, the ashless dispersant may comprise one or morealkenyl succinimides of an amine having at least one primary amino groupcapable of forming an imide group. The alkenyl succinimides may beformed by conventional methods such as by heating an alkenyl succinicanhydride, acid, acid-ester, acid halide, or lower alkyl ester with anamine containing at least one primary amino group. The alkenyl succinicanhydride may be made readily by heating a mixture of polyolefin andmaleic anhydride to about 180°-220° C. The polyolefin may be a polymeror copolymer of a lower monoolefin such as ethylene, propylene,isobutene and the like, having a number average molecular weight in therange of about 700 to about 2100 as determined by gel permeationchromatography (GPC).

Amines which may be employed in forming the ashless dispersant includewithout limitation any that have at least one primary amino group whichcan react to form an imide group and at least one additional primary orsecondary amino group and/or at least one hydroxyl group. A fewrepresentative examples are: N-methyl-propanediamine,N-dodecylpropanediamine, N-aminopropyl-piperazine, ethanolamine,N-ethanol-ethylenediamine, N-phenylenediamine, and the like.

Suitable amines may include alkylene polyamines, such as propylenediamine, dipropylene triamine, di-(1,2-butylene)triamine, andtetra-(1,2-propylene)pentamine. A further example includes the ethylenepolyamines which can be depicted by the formula H₂N(CH₂CH₂NH)_(n)H,wherein n may be an integer from about one to about ten. These include:ethylene diamine, diethylene triamine, triethylene tetramine,tetraethylene pentamine, pentaethylene hexamine, and the like, includingmixtures thereof in which case n is the average value of the mixture.These depicted ethylene polyamines have a primary amine group at eachend so they may form mono-alkenylsuccinimides andbis-alkenylsuccinimides. Commercially available ethylene polyaminemixtures may contain minor amounts of branched species and cyclicspecies such as N-aminoethyl piperazine, N,N′-bis(aminoethyl)piperazine,N,N′-bis(piperazinyl)ethane, and like compounds. The commercial mixturesmay have approximate overall compositions falling in the rangecorresponding to diethylene triamine to tetraethylene pentamine. Themolar ratio of polyalkenyl succinic anhydride to polyalkylene polyaminesmay be from about 1:1 to about 2.4:1.

In some embodiments, the ashless dispersant may comprise the products ofthe reaction of a polyethylene polyamine, e.g. triethylene tetramine ortetraethylene pentamine, with a hydrocarbon substituted carboxylic acidor anhydride made by reaction of a polyolefin, such as polyisobutene, ofsuitable molecular weight, with an unsaturated polycarboxylic acid oranhydride, e.g., maleic anhydride, maleic acid, fumaric acid, or thelike, including mixtures of two or more such substances.

The dispersant may contain at least one polyalkylene moiety. As afurther example, the dispersant, may comprise at least two polyalkylenemoieties. The polyalkylene moiety may have a molecular weight of fromabout 900 amu to about 3000 amu. The polyalkylene moiety polyalkylenemoiety may, for example, have a molecular weight of from about 1300 amuto about 2100 amu. As a further example, the polyalkylene moiety mayhave a molecular weight of about 2100 amu. The polyalkylene moiety maycomprise a polybutenyl group.

The dispersant may be dissolved in oil of suitable viscosity for ease ofhandling. It should be understood that the weight percentages given hereare for neat dispersant, without any diluent oil added.

The dispersant may be further reacted with an organic acid, ananhydride, and/or an aldehyde/phenol mixture. Such a process may enhancecompatibility with elastomer seals, for example. The dispersant mayfurther comprise a mixture of dispersants. As a further example, thedispersant may comprise nitrogen and/or may be free of phosphorus. Thedispersant may be present in an embodiment in the lubricating fluid inan amount of about 1 wt % to about 5 wt %.

The dispersant used in some embodiments of the present disclosure maycomprise a succinimide prepared from an alkenyl succinic acid oranhydride and ammonia. For example, the succinimide may comprise thereaction product of a succinic anhydride and ammonia. The alkenyl groupof the alkenyl succinic acid may be a short chain alkenyl group, forexample, the alkenyl group may comprise about 12 to about 36 carbonatoms. Further, the succinic anhydride may comprise a C₁₂ to about C₃₆aliphatic hydrocarbyl succinimide. As a further example, the succinicanhydride may comprise a C₁₆ to about C₂₈ aliphatic hydrocarbylsuccinimide. As an even further example, the succinic anhydride maycomprise a C₁₈ to about C₂₄ aliphatic hydrocarbyl succinimide.

The succinimide may be prepared from a succinic anhydride and ammonia asdescribed in European Patent 0 020 037, herein incorporated byreference. Further, the succinimide may comprise HiTEC® 3191 frictionmodifier, available from Ethyl Corporation. In some embodiments, nonon-metallic friction modifier other than the succinimide disclosedherein is included.

The succinimide may comprise one or more of a compound having thefollowing structure:

wherein Z may have the structure:

-   -   wherein R₁ and R₂ may be independently hydrogen or straight or        branched chain hydrocarbon groups containing from about 1 to        about 34 carbon atoms such that the total number of carbon atoms        in R₁ and R₂ is from about 11 to about 35; and    -   wherein, in addition to or in the alternative, the succinimide        may be formed by reacting maleic acid, anhydride, or ester with        an internal olefin containing about 12 to about 36 carbon atoms,        said internal olefin being formed by isomerizing the olefinic        double bond of a linear α-olefin or mixture thereof to obtain a        mixture of internal olefins.

One embodiment utilizes a poly-amine of the type tetra ethyl pentamine.Examples can include but are not limited to HiTEC® 646 Dispersant,available from Ethyl Corporation, and similar succinimide dispersants.

Extreme Pressure Additives

Extreme pressure agents known to those skilled in the art are useful inthe lubricant additive packages, lubricating oil, lubricated machines,and methods of the present invention. Also useful herein as extremepressure agents are sulfurized olefins, including but not limited tosulfurized isobutylene, alkylpolysulfides and sulfurized fatty acidesters.

Corrosion Inhibitors

Corrosion inhibitors of the thiadiazole and triazole classes aresuitable for use in this invention. Alkyl substituted thiadiazoles aswell as alkyl substituted triazoles are useful in this invention.

Other Agents

Antiwear and siloxane-containing polymer antifoam agents, well known tothose skilled in the art and as taught in, for example, U.S. Pat. No.5,492,638, can also be employed in the lubricant additive packages andfinished lubricating oils of the present invention.

A variety of oil-soluble sulphur-containing antiwear and/or extremepressure additives can be used in the practice of this invention.Examples are included within the categories of dihydrocarbylpolysulphides; sulphurized olefins; sulphurized fatty acid esters ofboth natural and synthetic origins; trithiones; sulphurized thienylderivatives; sulphurized terpenes; sulphurized oligomers of C₂-C₈monoolefins; and sulphurized Dieis-Alder adducts such as those disclosedin U.S. reissue patent Re 27,331. Specific examples include sulphurizedpolyisobutene of Mn 1,100, sulfurized isobutylene, sulphurizeddiisobutylene, sulphurized triisobutylene, dicyclohexyl polysulphide,diphenyl polysulphide, dibenzyl polysulphide, dinonyl polysulphide, andmixtures of di-tert-butyl polysulphide such as mixtures of di-tert-butyltrisulphide, di-tert-butyl tetrasulphide and di-tert-butylpentasulphide, among others.

Combinations of such categories of sulphur-containing antiwear and/orextreme pressure agents can also be used, such as a combination ofsulphurized isobutylene and di-tert-butyl trisulphide, a combination ofsulphurized isobutylene and dinonyl trisulphide, a combination ofsulphurized tall oil and dibenzyl polysulphide, and the like.

Reference should be had to EP 531 585 referred to above for furtherdetails concerning this component.

For purposes of this invention a component which contains bothphosphorus and sulphur in its chemical structure is deemed aphosphorus-containing antiwear and/or extreme pressure agent rather thana sulphur-containing antiwear and/or extreme pressure agent.

One such type of phosphorus- and nitrogen-containing antiwear and/orextreme pressure additives which can be employed in the practice of thisinvention are the phosphorus- and nitrogen-containing compositions ofthe type described in G.B. 1,009,913; G.B. 1,009,914; U.S. Pat. No.3,197,405 and/or U.S. Pat. No. 3,197,496. In general, these compositionsare formed by forming an acidic intermediate by the reaction of ahydroxy-substituted triester of a phosphorothioic acid with an inorganicphosphorus acid, phosphorus oxide or phosphorus halide, and neutralizinga substantial portion of said acidic intermediate with an amine orhydroxy-substituted amine.

Another type of phosphorus- and nitrogen-containing antiwear and/orextreme pressure additive which can be used in the compositions of thisinvention is the amine salts of hydroxy-substituted phosphetanes or theamine salts of hydroxy-substituted thiophosphetanes. Examples of thisgeneral type of antiwear and/or extreme pressure agent include the aminesalts hydroxyphosphetanes and the amine salts ofhydroxy-thiophosphetanes typified by Irgalube 295 additive (Ciba-GeigyCorporation).

Another useful category of phosphorus- and nitrogen-containing antiwearand/or extreme pressure agents is comprised of the amine salts ofpartial esters of phosphoric and thiophosphoric acids. For furtherdetails concerning this component, reference should be had to EP 531 585referred to above.

The formulations of the present invention have a total phosphoruscontent of not more than about 500 ppm. The formulations are alsoboron-free. By “boron-free” herein is meant substantially free of boronwhereby trace amounts of or contamination with low or unintended levelsof boron are to be included. Boron-free can herein include low levels ofboron up to about 25 ppm. By “substantially free of boron” herein ismeant less than about 50 ppm of boron.

NOTE: Current Boronated packages offered by Ethyl contain 125-150 ppm ofBoron. I think the above levels are too high.

Example Formulation

An example of an oil soluble lubricant additive package formulation ofthe present invention is outlined in the table below: COmponent Wt %Sulfurized olefin 30-50 Primary amine 0.1-5   Acid phosphate 0.5-5.0Rust Inhibitor 0.01-1   Antifoamant 0.2-2.0 Corrosion Inhibitor 0.2-2.0Diluent Oil 30-40 Dispersant   2-15.0

A finished oil comprising the preferred boron-free oil soluble lubricantadditive package was manufactured for testing purposes. The finished oilwas then tested by the L60-1 and the ISOT standard tests. It wasunexpected that a lubricant additive package could pass both the L60-1and ISOT standard tests without the inclusion of a boron source in theformulation. Phosphorus Boron L-60-1 ISOT Additive Dispersant ppm ppmC/V Sludge Beaker Rod Package A Yes 1,425 158 9.25 9.59 2.5 1 Package BYes 870 132 Package C Yes 680 0 8.0 9.0 Package D Yes 576 150 9.10 9.642.0 2.0 Package E Yes 525 195 9.10 9.54 2.5 2.5 Package F Yes 525 0 8.159.50 Package G NO 525 0 3.40 8.68 7.0 9.0 Package H NO 300 0 7.60 9.468.0 9.0 Invention Yes 300 0 9.44 9.52 1.5 2.0

The L60-1 test requires at least a 7.5 carbon/varnish (C/V) rating orhigher to pass, and at least a 9.4 sludge rating or higher to pass. TheL60-1 rating is based on a merit system with 10 indicating nocarbon/varnish and zero representing the worst rating.

The ISOT test, conversely, requires at most a 3.0 for varnish on theglass beaker and for varnish on the glass rod to indicate clean gearperformance. The ISOT rating is based on a demerit system with the bestISOT rating zero indicating no varnish and 9 representing the worstvarnish rating. This rating may also be described as thinly to lightlyadhering lacquer in the ISOT procedure. Note that prior art formulationscontaining phosphorus and boron pass both tests. Formulations with lowphosphorus alone do not pass both tests. Only the formulations of thepresent invention with both low phosphorus and a dispersant pass bothtests without boron.

The formulations of the present invention are especially effective inthe lubrication of vehicular axle gears and vehicular transmissiongears. The vehicles can be passenger cars, light duty trucks, heavy dutytrucks, buses, recreation vehicles, marine craft, and the like.

While the invention has been described in connection with what ispresently considered to be the most practical and preferred embodiments,it is to be understood that the invention is not to be limited to thedisclosed embodiment(s), but on the contrary, is intended to covervarious modifications and equivalent arrangements included within thespirit and scope of the appended claims, which are incorporated hereinby reference.

1. An oil soluble lubricant additive package comprising: (a) asuccinimide dispersant, (b) an antiwear agent, (c) an extreme pressureadditive, wherein the weight ratio of said dispersant to said extremepressure additive is from about 1:7 to about 1:2, and wherein thepackage is boron-free, and wherein the total phosphorus content of thepackage is not more than about 500 ppm.
 2. The oil soluble lubricantadditive package according to claim 1, wherein said dispersant isselected from the group consisting of: one or more of succinimidedispersants, succinamides, succinic esters, and succinic ester-amides.3. The oil soluble lubricant additive package according to claim 1,wherein said extreme pressure additive is selected from the groupconsisting of sulfurized olefins, sulfurized fatty acid esters, andalkyl polysulfides.
 4. A lubricating oil comprising: (a) a base oil; and(b) the oil soluble lubricant additive package of claim
 1. 5. Thelubricating oil according to claim 4, wherein said lubricating oilachieves a satisfactory score on at least one test selected from thegroup consisting of: ISOT test and L60-1 test.
 6. A machine lubricatedby the lubricating oil of claim
 4. 7. The machine according to claim 6,wherein said machine is selected from the group consisting of vehicularaxle gears and vehicular transmission gears.
 8. A vehicle comprising theoil soluble lubricating additive package of claim
 1. 9. A method forlubricating an axle assembly, said method comprising the steps of: atleast partially filling said axle assembly with a lubricant comprisingthe oil soluble lubricant additive package of claim
 1. 10. A method forlubricating at least one moving part, said method comprising the stepsof: contacting at least one said moving part with a lubricant comprisingthe oil soluble lubricant additive package of claim
 1. 11. An oilsoluble lubricant additive package comprising: (a) a dispersantcomprising no more than about 500 ppm of phosphorus, wherein saiddispersant is substantially free of boron; and (b) at least oneinhibitor, wherein the weight ratio of said inhibitor to said dispersantis from about 1:17 to about 4:5.
 12. The oil soluble lubricant additivepackage according to claim 11, wherein said dispersant is selected fromthe group consisting of: one or more of various types of ashlessdispersants including succinimides, succinamides, succinic esters, andsuccinic ester-amides.
 13. The oil soluble lubricant additive packageaccording to claim 11, wherein at least one said inhibitor is selectedfrom the group consisting of: corrosion inhibitors and oxidationinhibitors.
 14. The oil soluble lubricant additive package according toclaim 11, wherein at least one said inhibitor is selected from the groupconsisting of thiadiazoles and triazoles.
 15. A lubricating oilcomprising: (a) a base oil; and (b) the oil soluble lubricant additivepackage of claim
 11. 16. The lubricating oil according to claim 15,wherein said lubricating oil achieves a satisfactory score on at leastone test selected from the group consisting of: ISOT test and L60-1test.
 17. A machine lubricated by the lubricating oil of claim
 15. 18.The machine according to claim 17, wherein said machine is selected fromthe group consisting of automotive gear assemblies and automotivetransmission assemblies.
 19. A vehicle comprising the oil solublelubricating additive package of claim
 11. 20. A method for lubricatingan axle assembly, said method comprising the steps of: at leastpartially filling said axle assembly with a lubricant comprising the oilsoluble lubricant additive package of claim
 11. 21. A method forlubricating at least one moving part, said method comprising the stepsof: contacting at least one said moving part with a lubricant comprisingthe oil soluble lubricant additive package of claim
 11. 22. An oilsoluble lubricant additive package comprising: (a) a dispersantcomprising no more than about 500 ppm of phosphorus, wherein saiddispersant is substantially free of boron; and (b) at least one antiwearagent, wherein the weight ratio of said dispersant to said antiwearagent is from about 10:1 to about 2:1.
 23. The oil soluble lubricantadditive package according to claim 22, wherein said dispersant isselected from the group consisting of: one or more of various types ofashless dispersants including succinimides, succinamides, succinicesters, and succinic ester-amides.
 24. The oil soluble lubricantadditive package according to claim 22, wherein at least one antiwearagent is selected from the group consisting of: dihydrocarbylpolysulphides; sulphurized olefins; sulphurized fatty acid esters ofboth natural and synthetic origins; trithiones; sulphurized thienylderivatives; sulphurized terpenes; sulphurized oligomers of C2-C8monoolefins; and sulphurized Dieis-Alder adducts.
 25. A lubricating oilcomprising: (a) a base oil; and (b) the oil soluble lubricant additivepackage of claim
 22. 26. The lubricating oil according to claim 25,wherein said lubricating oil achieves a satisfactory score on at leastone test selected from the group consisting of: ISOT test and L60-1test.
 27. A machine lubricated by the lubricating oil of claim
 25. 28.The machine according to claim 27, wherein said machine is selected fromthe group consisting of vehicular axle gears and vehicular transmissiongears.
 29. A vehicle comprising the oil soluble lubricating additivepackage of claim
 22. 30. A method for lubricating an axle assembly, saidmethod comprising the steps of: at least partially filling said axleassembly with a lubricant comprising the oil soluble lubricant additivepackage of claim
 22. 31. A method for lubricating at least one movingpart, said method comprising the steps of: contacting at least one saidmoving part with a lubricant comprising the oil soluble lubricantadditive package of claim
 22. 32. An oil soluble lubricant additivepackage comprising: (a) a dispersant comprising no more than about 500ppm of phosphorus, wherein said dispersant is substantially free ofboron; and (b) at least one antifoam agent, wherein the weight ratio ofsaid dispersant to said antifoam agent is from about 30:1 to about 5:1.33. The oil soluble lubricant additive package according to claim 32,wherein said dispersant is selected from the group consisting of: one ormore of various types of ashless dispersants including succinimides,succinamides, succinic esters, and succinic ester-amides.
 34. The oilsoluble lubricant additive package according to claim 32, wherein atleast one antifoam agent is selected from the group consisting ofsiloxane-containing polymers.
 35. A lubricating oil comprising: (a) abase oil; and (b) the oil soluble lubricant additive package of claim32.
 36. The lubricating oil according to claim 35, wherein saidlubricating oil achieves a satisfactory score on at least one testselected from the group consisting of: ISOT test and L60-1 test.
 37. Amachine lubricated by the lubricating oil of claim
 35. 38. The machineaccording to claim 37, wherein said machine is selected from the groupconsisting of: vehicular axle gears and vehicular transmission gears.39. A vehicle comprising the oil soluble lubricating additive package ofclaim
 32. 40. A method for lubricating an axle assembly, said methodcomprising the steps of: at least partially filling said axle assemblywith a lubricant comprising the oil soluble lubricant additive packageof claim
 32. 41. A method for lubricating at least one moving part, saidmethod comprising the steps of: contacting at least one said moving partwith a lubricant comprising the oil soluble lubricant additive packageof claim
 32. 42. The lubricating oil according to claim 4, wherein saidlubricating oil achieves a satisfying score on the ISOT test and theL60-1 test.
 43. The lubricating oil according to claim 15, wherein saidlubricating oil achieves a satisfying score on the ISOT test and theL60-1 test.
 44. The lubricating oil according to claim 25, wherein saidlubricating oil achieves a satisfying score on the ISOT test and theL60-1 test.
 45. The lubricating oil according to claim 35, wherein saidlubricating oil achieves a satisfying score on the ISOT test and theL60-1 test.